The rectangular cassette for the storage of a compact disk is known, this cassette being constituted from a case formed from a base, a cover, made from plastic material which is usually transparent, and a disk-holder which is inserted and clamped in the base and which is made from a plastic material which is usually dark.
The base of the case comprises a flat rectangular bottom and four walls. The two lateral walls have a cutout in the middle in order to avoid friction between the disk and the wall and in order to facilitate the grasping, positioning or extraction of this disk. Between the base and the disk-holder it is possible to insert an illustrated title sheet referring to the disk. This sheet extends along the front and rear walls to allow the title also to be read on the edges of the cassette once stored.
The cover comprises an upper rectangular wall, almost square, slightly shorter than the base. Two lateral walls rise from this wall and extend towards the rear, forming flexible arms fitted with spindles which engage in corresponding holes at the rear of the base and which form a pivoting axis for the cover with respect to the base. This allows the cover to be closed or opened through 180.degree..
The lateral walls of the cover comprise six small inward-facing semicircular extensions (three per side) leaving a certain clearance between them and the upper wall of the cover which allows a booklet with an illustrated cover page relating to the disk to be slid along this wall and to be held there. At the rear, the booklet abuts against a rear wall having the thickness of the booklet. At the front the booklet is stopped by two small protuberances.
The side walls of the base are recessed by the thickness of the lateral walls of the cover. Thus, when the case is closed, the latter are positioned on the edges of the bottom of the base and enclose the lateral walls of the base inside them. At the same time, the cover, having no front wall, rests on the edge of the front wall of the base.
The disk-holder which is also rectangular comprises, along its rear edge, a raised strip which, when the casing is closed, is disposed in the same plane as the upper wall of the cover. The disk-holder comprises raised areas at the four corners and a circular housing at a lower level. The surface of this housing is provided for protecting the disk. At the centre, there is hole corresponding to the central hole of the disk. Concentric with this hole there is a small slightly raised disk which constitutes a bearing surface for the inner circular area of the disk which does not carry data. In this way, the entire area containing data floats freely in the circular housing of the disk-holder, avoiding any contact or friction between the recordings of the disk and the package. Around the central hole there are cut-out segments comprising hooks which hold the edge of the hole of the disk with a pawl effect.
Despite the high density of data recorded on digital audio disks, which allows a playing time of more than one hour, certain works exceed this time. Because of this there is a requirement for casings which allow several disks to be stored in the same package.
The European patent No. 114631 describes such a casing. This casing comprises two bases, with their disk-holder, identical to that of the single disk cassette described above, which articulate on a new median part. The assembly forms a casing whose thickness is twice that of the single disk cassette. In this casing, each of the bases with its disk-holder can carry one disk and the median part can furthermore carry an additional disk on one or both faces. The casing can therefore contain two to four disks. The two bases, identical to the base described above require no further description. They differ only in their function which, in the casing, becomes a cover instead of a base.
The median part comprises an almost square rectangular plate, and two lateral walls whose height is twice of that of the lateral wall of the cover of the single disk cassette. The lateral walls of the median part extend towards the rear forming flexible arms, provided with two spindles per side. The latter each engage in a hole at the rear of a base and form a pivoting axis for these bases (which have become covers).
The median part is provided with a profiled strip at the front, whose height is less than that of the lateral walls. The edges of this strip form a bearing surface for the butt edges of the covers. At the rear there is also a profiled strip similar to the one at the front.
The rectangular plate of the median part comprises four semicircular openings at the corners, which represent a saving in material and serve for the insertion of fingers for grasping, inserting or extracting the disks. There is a hole at the centre. If the casing is intended to receive three or four disks, a raised support part with segments and hooks is inserted in this hole in order to hold an additional disk on one or both faces. The raised support part, the segments and the hooks are similar to the equivalent parts in the single disk cassette and perform the same functions.
The multi-disk casing of the patent EP 114631 is therefore provided for recordings whose playing time exceeds that of a single compact disk. Practical experience has however shown that in 70% of cases the casing contains only two compact disks. The package limited to two disks in the casing described above results in relatively high costs and volumes with respect to the cost and volume of the offered disks. Furthermore, the thickness of this casing does not allow it to be stored in the conventional storage means provided with compartments having the thickness of single disk cassettes. Finally, its manufacture involves at least five components, namely the two covers, the two disk-holders which are inserted in them and the median part which allows the articulation of the assembly. In production, the manufacture of this casing requires a manufacturing time which is twice that of the single disk cassette.
The European patent application No. 420350 attempted to overcome these disadvantages by proposing a casing for two disks which has the same dimensions as the conventional single disk cassette and which comprises a reduced number of parts and moulds, which represents a significant saving at the manufacturing stage.
This patent application describes a casing constituted from a rectangular median disk-holder provided with a cover for each face. These covers articulate by means of spindles and holes on two diagonally opposite sides of the disk-holder, such that the assembly opens in a zigzag manner.
The median disk-holder part comprises a rectangular plate and two lateral walls. At the front and at the rear, the plate is slightly raised in a staggered manner in order to provide an articulation surface for each cover. The plate between these raised sections comprises semicircular cutouts at the four corners. These cutouts, which can be partially blocked in opposite pairs, allow the disks to be grasped, positioned or extracted. At the centre, on each face, a thicker circular part serves as a support for the area of the disk having no recordings. This part projects segments towards the central hole, these segments which carrying teeth pointing alternately towards one cover or the other. They are intended for fixing or releasing, with a pawl action, the disks which are placed on them or removed from them.
The covers each comprise an upper rectangular wall with two lateral walls. The bottom is folded into C-shape at the rear. The lateral walls each comprise two strips which are curved towards the inside leaving gaps into which can be slipped a title sheet or booklet with an illustrated cover page. The sheet extends rearwards, folds back and thus also indicates the title of the disk on the edge. The same thing is done under the other cover for the disk located there. Thus the casing contains two faces which are printed differently according to the disk which it contains.
The casing of the patent application EP 420 350 does however have the disadvantage that it opens in a zigzag manner with pivoting axes on two opposite faces. This is not very convenient in comparison with the preceding casings which open like a book with pivoting axes on the same side and on the same face. In the case of the patent application EP 420 350 there is a risk of turning the casing in all directions while seeking the appropriate opening for the required disk. Furthermore, when a cover is opened and it is desired to extract the disk by inserting the fingers in the semicircular openings, the pressure of the fingers risks the application of a pressure on the disk on the other face and on its cover causing the disk to fall with the risk of damaging it. Furthermore, this casing cannot be manufactured on conventional single disk cassette production lines nor on conventional assembly machines. The latter must place disks on the median disk-holder part. Now, they are interfered with by the covers which open in zigzag manner and which require machines for vertical assembly. Furthermore, the tenon system of this patent application does not hold the disks sufficiently firmly for the positioning of one disk to prevent the other from falling. Furthermore the disk-holder is not very appropriate for stacking, neither during manufacture nor during assembly. This goes also for the machines for inserting title sheets and booklets, given that two different title sheets are necessary for the two faces in zigzag configuration. Furthermore, these sheets have a type of folding which is different from that of the conventional title sheets of single disk cassettes.
The European patent application No. 430 956 describes a casing for two disks comprising a base, a cover and a disk-holder tray. The base and the cover are similar to those of the single disk cassettes described above. The disk-holder tray comprises a rectangular plate, almost square, and a raised strip having the same function as that of the tray of the conventional single disk cassette. The tray pivots along an axis located along the wall of the base (called front wall), opposite to the one (called rear wall) along which the cover pivots, the tray and the cover pivoting on the same face of the base. The disk-holder tray is provided with a tenon system similar to that described in the patent application EP 420 350.
The casing described in the patent application EP 430 956 does however have numerous disadvantages. The arrangement of the pivoting axis of the disk-holder tray does not allow it to open completely, that is to say through 180.degree.. Because of this, the casing assembly and more particularly the tray, are in a position which is not very stable when it is desired to withdraw or position the disk carried by the lower face of the tray. Another disadvantage of this casing is that the trays cannot be stacked on each other in a stable manner, which prevents automated manufacture and automated assembly of all of the parts of the casing.
The present invention tends to overcome the defects of the known casings. It proposes a storage casing for a data medium in the form of disks with high recording density, known as compact disks, and more particularly for the storage of from one to six disks.
The particular intention is to provide a casing for the storage of one or two disks, this casing having the same outer dimensions as those of conventional single disk cassettes or to provide a casing for the storage of one to six disks, this casing having the same outer dimensions as those of multi-pack casings allowing the storage of one to four disks.
One of the purposes of the invention is in particular to provide a casing which can be manufactured and assembled on the conventional manufacturing lines used for the known single disk cassettes or the known multi-pack casings. It is particularly intended that the manufacture and assembly of the casing according to the invention can be carried out in a completely automated manner. In particular, the disk-holder trays must be stackable on each other in a stable manner, this stacking also having to be possible when the trays carry the disk or disks. This is important throughout the steps of manufacturing and assembling of parts. It is furthermore intended that the stacking of trays can be slightly readjusted in the lateral direction, as in the forward-backward direction, and that this can be done in a completely automated manner. Furthermore, the disk-holder tray, fitted with the disk or disks, must be able to be positioned in the base in an automated manner.
Another purpose of the invention is to provide a casing comprising one or two universal bases able to contain, by choice, one or two trays, these trays being capable of carrying one disk or capable of carrying two compact disks. These trays are interchangeable.
Another purpose of the invention is also to provide a casing for at least one disk, this casing being of high quality but inexpensive, in the sense that it comprises a minimum number of different parts to be moulded.
The purpose of the present invention is also to provide a casing whose tray is provided with a fixing system providing good holding of the disks without the risk, in particular, of one disk falling when the other one is extracted from the fixing system, in the case in which the tray carries two disk. It is also intended to provide a casing whose fixing system or systems are very flexible and therefore supple. This fixing system allows the positioning and withdrawal of the disks in a practical, simple and secure manner.